Rat Anti-Mouse Cd44 Heterohybridoma [LN814]

The efficient delivery of chemotherapeutic drugs to the tumor tissues unavoidably encounters numerous obstacles, such as poor tumor targeting capability, slow intracellular drug release and massive accumulation in the liver. In this study, by self-assembling methoxy poly (ethylene glycol)-poly (lactide) block copolymer (mPEG-PLA) and hyaluronic acid-paclitaxel conjugate (HA-PTX), the composite nanoparticles (mPPHP NPs) were fabricated for efficient therapy of cancer. mPPHP NPs formed self-assembled nanoparticles (116 nm in diameter) with a narrow size distribution; and showed a rapid release of PTX in the presence of hyaluronidase and esterase. mPPHP NPs exhibited enhanced internalization by cells via CD44 receptors and selected cytotoxicity against A549 cells in vitro. More importantly, compared with other PTX formulations, mPPHP NPs were demonstrated to present the reduced liver accumulation, excellent tumor-targeting ability and superior antitumor efficacy in vivo, with a TIR of 75.9%. The multifunctional composite nanoparticles could be developed as a promising nano carrier for improved therapeutic efficacy.

Exosomes secreted from tumor cells can remodel the tumor environment by promoting tumor metastasis and multidrug resistance. The aim of this study was to analyze the proteome profile of the breast cancer line resistant to doxorubicin resistance (MCF-7/ADR) by liquid chromatography linked to tandem mass spectrometry assay (LC-MS/MS). Our results revealed that DOX increases the exosomes release from MCF-7/ADR cells and the exosome-mediated proteins intercellular transfer in breast cancer chemoresistance regulation. The expression of the candidate target exosomic CD44 in DOX-resistant cells (A/Exo) was higher than in parental breast cancer cells (S/Exo), and the increasing levels of exosomic CD44 (21.65-fold) were higher than those of cellular CD44 (6.55-fold) (allp< 0.05). Similar results were obtained in clinical samples; exosomal CD44 in the serum of nonresponders was significantly higher than that in the chemotherapy-responsive group (p< 0.05). Also, we modified the MCF-7-derived exosomes loaded with siRNA against CD44 to observe the effects of targeting reduced CD44 expression in luminal A breast cancer cells. Exosome-siRNA targeted CD44 (Exos-siCD44) could efficiently silence its expression. When cocultured on Exos-siCD44, breast cancer cells exhibited reduced cell proliferation and enhanced susceptibility to DOX. The same phenomenon was observed in mice. In conclusion, breast cancer cells could spread resistance capacity by the intercellular transfer of proteins, especially CD44, via exosomes.